Real world / hypothetical world / thought-experiment aside, the point stands: treating a service as an entitlement entails imposing an obligation on somebody else to provide that service, OR to pay for that service, etc.
If granting one person a "right" means violating someone else's rights (that is, their right to choose how to direct their energy and the fruits of their labor) then it's unjust.
If granting one person a "right" means violating someone else's rights (that is, their right to choose how to direct their energy and the fruits of their labor) then it's unjust.